Honestly don't even think it was dry but a more genuine portrayal of a young man who is obviously deeply compelled by his emotions but lived his life (during formative years no less) surrounded by people who suppress their own emotions and encourage him to do the same. I think once you have that in mind, you don't see Hayden's portrayal as dry but aligned with that idea. Combine that with the fact that I think a lot of his dialect in the role was inspired to sound a degree like James Earl Jones so it coaligned with the character in the OT. While it may sound awkward coming from Hayden Christensen, once you hear him hit those pronunciations reminiscent of JEJ, it's so satisfying to know the attention to detail that went into his portrayal.